Mica cigarette winding machine



Nov. 7, 1939.

H. w. WEBB MICA CIGARETTE WINDING' MACHINE Filed Aug. 29, 1936 2 Sheets-Sheet l gmc/whole Nov. 7, 1939. H. w. WEBB MICA CIGARETTE WINDING MACHINE Filed Aug. 29, 1936 2 Sheets-Sheet 2 Patented Nov. 7, 1939 Hartwell W. Webb, Flint, Mich., assigner to General Motors Corporation, Detroit, Mich., a, corporation of Delaware Application August 29, 1936, Serial No. 98,557

6 Claims.

The winding of mica cigarettes on the electrodes of mica insulated spark plugs has been a costly manual operation. It required the services of a highly skilledL worker and even then was slow and tedious. At hest, it was very waste'iul of material because the strips of mica employed were frequently broken or scratched or rendered unserviceable by lms of oil from the hands of the worker.

This invention has to do with a machine by which mica cigarettes may be wound on the electrodes of mica insulated spark plugs cheaply, quickly and easily and with very little waste of material even by a worker who has had very little training.

For a detailed disclosure of such a machine, reference is made to the `accompanying drawings and the following specication where it is shown and described.

In the accompanying drawings:

Figure 1 is a top plan View of a machine in accordance with my invention with a spark plug electrode in place init;

Figure 2 is a fragmentary front elevation oi the machine;

Figure 3 is an end elevation oi the machine with Parts broken away and in section and in different positions than those in which they are shown in Figure l;

Figure 4 is an enlarged fragmentary view of the roller chain which is incorporated in the machine;

Figure 5 is an enlarged View, mainly in section, of a portion of the machine with the parts in the positions in which they are shown in Figure 3;

Figure 6 shows a spark plug electrode with a mica cigarette wound on it.

The basis of the machine shown in the draw-y ings is a small lathe which consists of a bed it on which there are mour. ed a headstock il and a tailstock l2. In the headstock, there is journaled a spindle i3 on 'which there are secured a series of driving pulleys iii. In the tailstock, there is journaled a spindle l5 which may be moved back and forth lengthwise and held in any desired position by a lock operated by a handle E6. The spindle i3 carries a chuck l'i which may be opened and closed by a knob i3. vInto the inner end 0i the spindle l5, there extends a bore, i9 which is designed to accommodate one end of a spark plug electrode.

In a depression in the hed It between the headstock ll and the tailstock l2 there is mounted a crosspiece 2d. In the upper surface of the crosspiece on one side of the axis of the spindles i3 and i5, there are formed ways which extend at a right angle to the axis oi the spindles. In the ways, there is mounted so that it may slide lengthwise thereof a plate El whose upper surface is preferably chromium plated and polished.

To the inner end oi the plate 2l, there is connected a roller chain 22 which is approximately equal in width to the plate. The chain consists of three sets oi elongated links 23 with a triangular link 2d at one end of each set separated from cach other crosswise of the chain. The elongated links of the several sets are connected in series one to another by pintles 25 which extend the full vwidth ci the chain and through their overlapping ends. The triangular links are connected to the outer ends of the elongated links at one end ci the sets by another pntle 25 which extends through the latter and through the former near one of their apices. The triangular links are also connected to each other by pins 26 similar to the pintles 25 which extend through them near their other apices. The outer ends of the elongated links at the other end of the sets extend into notches 2l in the inner end of the plate 2l and are connected thereto by a pintle 28 which extends through them and the` inner end oi the plate. On each of the pintles 25 and pins 2E, there are sleeved so that they may rotate on the pintles and pins four rollers 29 which are preferably chromium plated and polished. One of these rollers is disposed between the intermediate and each of the outer sets of links and one is disposed on the outer side of each of the outer sets of links. The several elements of the chain are maintained in assembled relation by cylindrical nuts 3i! threaded on the pintles 25 and pins 255 and disposed in counterbores in the cuter ends of the outer rollers 29.

To hold the chain 22 wrapped around a spark electrode disposed between the spindles i3 and l5, as shown in Figures 3 and 5, there are provided hooks 3l which may engage over eX- tensions 32 oi the pin 26 which is outermost when the chain is wrapped around the electrode. Each of the hooks 3i is secured to one end of a shaft 33 which extends through and is journal-ed in the crosspiece 2G. The hooks 3i are urged to the positions in which they engage over the extensions ?32 oy a spring 3d which is disposed within a bore in the crosspiece 2Q and engages a dat on the shafts?, through the intermediary of a plunger 35 but may loe moved to free the outer end ci the chain so that it may he unwrapped sary.

from the electrode by depressing one of the fingers 36 which are formed as angularly disposed extensions of the hooks 3|. One of the hooks 3| is disposed in a shallow recess 43 in the side of the crosspiece 20 and movement of the hooks in the direction in which they are urged by the spring 34 is limited by engagement of this hook with a wall of the recess.

So that the chain 22 will snugly embrace the spark plug electrode disposed between the spindles I3 and I5 and may accommodate itself to the increase in the diameter of the work as the operation oi winding the mica cigarette on the electrode proceeds, there is provided a spring 31 which is disposed in a bore in the arm of the crosspiece 20 on which the plate 2| is mounted and tends to move the plate away from the axis of the spindles I3 and I5 through the intermediaries of a plunger 38 and a setscrew 39 which extends through a lug 40 secured to the lower side of the plate.

On the arm of the crosspiece 2|! which is disposed on the opposite side of the axis of the spindles I3 and I5 from that on which the plate 29 is mounted, there is mounted an indicator 4|. The indicator 4| is so mounted that it may be moved from the inoperative position in which it is shown in Figure l to the position in which it is shown in Figure 3 in which its feeler 42 engages one of the rollers 29 of the chain 22 and it indicates the thickness of the mica cigarette which has been wound on the spark plug electrode disposed between the spindles I3 and I5.

In using the machine shown in the drawings and hereinbefore described, the operator places an electrode a on which a mica cigarette b is to be wound in the machine with one end secured in the chuck Il and the other inserted in the bore I9 in the spindle I5. Then the operator slides the plate 2| toward the axis of the spindles I3 and I and wraps the chain 22 around the electrode and engages the extensions 32 under the hooks 3| as shown in Figures 3 and 5. After these things have been done, the operator places a strip c of mica on the plate 2| and slides it toward the axis of the spindles I3 and I5 until its inner end is engaged between the lower side of the electrode a and the chain 22. Then, by turning the pulley assembly I4, the operator rotates the electrode a in a clockwise direction when viewed as shown in Figures 3 and 5. This rotation of the electrode, as Figure 5 indicates, causes the strip of mica c to be wound around the electrode. After all except the end of the strip of mica has been wound around the electrode, the operator slides another strip along the plate 2| until its inner end is engaged between the unwound end of the rst strip and the portion thereof that has been` wound on the electrode and again rotates the electrode to wind the second strip around it and the rst. Additional strips are similarly wound around the electrode and the strips previously wound on it until a test by the indicator 4| shows that the cigarette b is of the desired thickness. Then the hooks 3i are disengaged from the extensions 32, the chain 22 unwrapped from around the electrode and the cigarette and the electrode with the mica cigarette wound on it removed from the machine.

When the machine shown in the drawings and hereinbefore described is used very little han dling of the mica strips c by the operator is neces- Therefore, and because the only parts of the machine with which the stripsvcontact (the plate 2| and the rollers 29) are smooth and highly polished and the strips have rolling, not sliding, contact with the chain 22, wastage of mica strips as a result of breaking, cracking and soiling and rejects of spark plugs due to defects in the mica cigarettes are minimized. The operation of winding mica cigarettes is rendered much faster and less tedious by my machine. Moreover, mica cigarettes produced by my machine are much more uniform than those produced by hand because the tightness of the turns of the mica strips is automatically determined by the spring 31. All of these things contribute to the production of better spark plugs more cheaply when my machine is used than when the mica cigarettes are wound by hand.

I claim:

1. In a machine for winding material, a flexible member within which the material may be wound and a shelf over which the material may be advanced into the flexible member and to which one end of the latter is anchored, the shelf being adjustable lengthwise of the flexible member so that the latter may accommodate itself to the increase in diameter of the product as the winding operation proceeds.

2. In a machine for winding material, a flexible member Within which the material may be wound, a shelf over which the material may be advanced into the flexible member and to which one end of the latter is anchored, the shelf being adjustable in the direction of the length of the exible member so that the latter may accommodate itself to the increase in diameter of the product as the winding operation proceeds, and means for releasably anchoring the other end of the flexible member so that it may be unwrapped from around the product.

3. In a machine for winding material, a ilexible member which is anchored at one end and within which the material may be wound, a shelf over which the material may be advanced into the iiexible member and to which the other end of the flexible member is anchored, the shelf being adjustable in the direction of the length of the flexible member, and means for resiliently urging the shelf in the direction to wrap the flexible member more tightly around the wound material.

4. In a machine for winding strip mica on a spark plug electrode, means for supporting a spark plug electrode so that it may be rotated, a shelf over which strip mica may be advanced toward the spark plug electrode movable toward and away from the axis thereof, a roller chain which may be wrapped around the spark plug electrode anchored at one end to the end of the shelf nearest the spark plug electrode, means for releasably anchoring the other end of the chain when it is wrapped around the spark plug electrode, and means for yieldingly urging the shelf away from the spark plug electrode so that the chain will snugly embrace it.

5. In a machine for winding material on a mandrel-like member, means by which the mandrel-like member may be supported and rotated, a roller chain within which the material may be wound on the mandrel-like member anchored at one end, a triangular link with rollers journalled near two of its apices at the other end of the chain, and means which engages the triangular link near the other of the apices to hold the rollers which are journalled therein against the material wound on the mandrel-like member.

6. That improvement in the art of manufacturing mica insulated spark plugs which consists of enV Wound on it around the electrode, means including a resilient member for anchoring one end of the chain so that it will snugly embrace the stripy mica wound on the electrode and yet accommodate itself to the increase in the diameter of the product which occurs during the winding operation, and means including a releasable catch fory anchoring the other end of the chain so that it may be vunWrapped from around the product when the Winding operation is completed.

HARTWEIL W. WEBB. 

